esAsm

esAsm is a toy assembly-like language

Installation

raco pkg install esAsm

The esAsm language

• Each line in an esAsm file may contain whitespace, a comment, a label, or an instruction.
• Comment lines begin with ; and are ignored. Lines starting with #lang esAsm are also ignored.
• Labels are indicated with the suffix :. The : is not part of the label name when referenced elsewhere.
• Literal integers are prefixed with #, and register references are prefixed with r. The registers are r0-r11.
• Program execution is moved to the beginning of a file when the end is reached. It will continue looping until the hlt instruction.

Instructions

In this documentation, val means any literal or register, reg means a register, and lab means a label.

• shn val prints the numeric value of val.
• sha val prints the ascii character with the decimal value val.
• mov reg val sets the value of reg to val.
• add reg val1 val2 sets the value of reg to val1 + val2.
• sub reg val1 val2 sets the value of reg to val1 - val2.
• jmp lab moves the program execution to lab.
• jlt lab val1 val2 moves the program execution to lab if val1 < val2.
• jgt lab val1 val2 moves the program execution to lab if val1 > val2.
• jet lab val1 val2 moves the program execution to lab if val1 == val2.
• inp reg sets the value of reg to an integer from read from stdin.
• hlt ends the execution of the program.
• mficofsr reg sets the value of reg to the value of the "Is Computer On Fire" status register. See here.

Examples

There are a few examples in the examples/ directory.

• read-six-numbers.es.rkt reads six numbers and prints their sum.
• is-even.es.rkt prints Y if the given number is even and N if it's odd.
• compare.es.rkt prints G, L, or E if the first number is respectively greater, less, or equal to the second.
• fibonacci.es.rkt prints the first 10 terms of the Fibonacci sequence.
• factors.es.rkt prints the factors of a given number.
• no-jump.es.rkt demonstrates the branchless sublanguage.

For testing purposes, inp is replaced (commented) in the examples.

Instruction reference

Name	Summary	Syntax
shn	Show as number	shn val
sha	Show as ascii	sha val
mov	Move	mov reg val
add	Add	add reg val1 val2
sub	Subtract	sub reg val1 val2
jmp	Jump	jmp lab
jlt	Jump if less than	jlt lab val1 val2
jgt	Jump if greater than	jgt lab val1 val2
jet	Jump if equal to	jet lab val1 val2
inp	Input	inp reg
hlt	Halt	hlt
mficofsr	Move From Is Computer On Fire Status Register	mficofsr reg

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All contributions are welcome by pull request or issue, especially new instructions.

Behavior of esAsm is undefined if the computer is on fire.

esAsm is licensed under the MIT license. See LICENSE for full text.